Objective:To observe the tansdifferentiation of bone marrow mesenchymal stem cells(MSCs) into cardiomyocyte in a coculture system with cardiomyocytes.Methods:Newly born Wistar Rats’ cardiomyocytes were isolated and cultured and the cells were labeled with DAPI.Prepared MSCs were planted into the cardiomyocytes dishes to establish a co-culture system.Supernatant liquid of the cardiomyocytes or fibroblast was added the MSCs(non-labeled) dishes as the control. After one week of coculture

fluorescence microscope observation and immunocytochemical staining with cTnT was performed to evaluate the phenotype changes in non-labeled MSCs.Results:MSCs and cardiomyocytes were connect with each other by net in culture plate after a few days of coculture;some non-labeled cells were positively stained by cTnT antibody while the MSCs cultured with cardiomyocytes or fibroblast supernatant liquid were stained negatively.Conclusion:To obtain cardiomyocyte phenotype in vitro

direct contact of MSCs with cardiomyocytes is essential.The signaling molecules induce MSCs’ transformation into cardiomyocytes are likely some membrane proteins on the surface of cardiomyocytes.